1912

This was the first time that candidates were chosen through primaries. President
William Taft ran to become the nominee, and faced the opposition of former President
Theodore Roosevelt. Roosevelt won most of the states and received more than a half of popular vote. He even defeated Taft in his home state of Ohio. However Taft received more delegates than Roosevelt and thus was nominated during the convention. Roosevelt founded a new party, the
Progressive Party and challenged Taft and Democratic nominee
Woodrow Wilson in the general election. Wilson won the election, gaining a large majority in the
Electoral College and winning 42% of the popular vote, while Roosevelt won 27% and Taft 23%.

1932

As the year 1932 began, the Republican Party believed Hoover's protectionism and aggressive fiscal policies would solve the depression. Former Senator of Maryland
Joseph France was the major opponent of incumbent President
Hoover and won the most states. Despite France's success in the primaries, President
Herbert Hoover controlled the party and had little trouble securing a re-nomination. Soon afterwards Hoover lost the election to Democratic nominee
Franklin Roosevelt.

1936

Following the
landslide defeat of incumbent president
Herbert Hoover by Democrat
Franklin D. Roosevelt, the Republican Party sought its first nominee to attempt to unseat the largely popular incumbent president. There were six candidates in total, but four of them were seen as "favorite son" candidates who only won their respective home states:
Earl Warren of California,
Frank Knox of Illinois,
Stephen A. Day of Ohio, and
Warren E. Green of South Dakota. Thus, the only two serious candidates were Governors
William Borah of Idaho and
Alfred "Alf" Landon of Kansas. Although Borah won more states' primaries, more total popular votes, and a larger percentage overall (with 5 states to Landon's 2), Landon managed to use his connections to the party machinery to secure a majority of necessary delegates at the convention, and became the nominee. Knox was chosen as Landon's running mate.

1940

After Landon's even larger landslide loss to Roosevelt in 1936, the party sought out more moderate candidates for the nomination in 1940. There were twice as many candidates as in 1936, with 12, including former President Hoover. However, only three won any primaries: Senate Minority Leader
Charles L. McNary of Oregon, Senator
Robert A. Taft of Ohio, and
Manhattan District AttorneyThomas Dewey of New York. Dewey won 5 states, while McNary and Taft won only one state each. However, later on in the primaries, businessman
Wendell Willkie began to gain momentum due to his lack of political experience and for being a new face in the political scene. He ultimately managed to win a majority of necessary delegates at the convention, primarily when the delegates of Michigan, Pennsylvania, and New York switched their allegiances to vote for Willkie. McNary was ultimately chosen as Willkie's running mate.

1944

Willkie had come closer to defeating Roosevelt than Hoover or Landon, but still lost substantially. At this point, a divide appeared in the Republican Party between the moderates and the conservatives, each claiming that only a candidate with their beliefs had a chance at beating Roosevelt as he ran for an unprecedented fourth term. The 1944 primaries saw 10 major candidates, which included former candidates Earl Warren and Thomas Dewey, as well as the previous nominee Wendell Willkie. One prominent candidate was General
Douglas MacArthur, who was popular among conservatives and won 2 states and the most total popular votes and vote percentage, but was unable to campaign effectively or attend the convention due to still planning Allied strategies in the midst of
World War II. Thus, the conservative support shifted from Robert Taft in the previous election to Governor
John W. Bricker of Ohio, while the moderates supported Governor Dewey of New York, who won the most primaries with 3. Dewey ultimately secured the nomination at the convention, and selected Bricker as his running mate.

1948

Although Dewey had also lost to Roosevelt in 1944, Roosevelt had died in office shortly thereafter, and incumbent President
Harry S. Truman was widely unpopular and thus seen as easy to beat. The 1948 primaries set the record for the highest number of candidates in the history of the Republican Party, with 15 total; a record it held for nearly 70 years until 2016 surpassed it. Among them were repeat candidates Douglas MacArthur, Senator Robert Taft, Governor Earl Warren, Businessman
Riley A. Bender of Illinois, and the previous nominee Thomas Dewey. Although Warren claimed the highest vote total with his sole win in California, the top two candidates were moderate Republican Dewey and former Governor
Harold Stassen of Minnesota, a more liberal Republican who had previously run in 1940 and 1944. Stassen won more primaries with 4 to Dewey's 2, but after Stassen was perceived as losing the first-ever broadcast presidential debate with Dewey (on the issue of outlawing
Communism in the United States), Dewey went on to easily claim the nomination for a second consecutive time (the first non-president in the Republican Party's history to do so). Warren was chosen as Dewey's running mate.

1952

Having suffered five consecutive losses, the Republican Party sought out a candidate who could appeal to voters all across the political spectrum, possibly through name recognition. Once more, a divide emerged between the conservative wing of the party and the liberal wing. The conservatives were once again represented by Senator Robert Taft, while the liberals were represented by General
Dwight D. Eisenhower. Other candidates included Governor Earl Warren of California and former Governor Harold Stassen of Minnesota. Taft narrowly won more victories than Eisenhower, with 6 primaries to Eisenhower's 5. The race was neck-and-neck by the beginning of the convention, but Eisenhower's supporters (including, most prominently, former two-time nominee Thomas Dewey and Senator
Henry Cabot Lodge, Jr.) accused Taft of corruption by convincing state party leaders in Texas and Georgia to give him all their delegates, rather than award them proportionately and therefore give some to Eisenhower. The delegates at the convention ultimately agreed and voted to support the "Fair Play" amendment 685–548, which convicted Taft of such and gave the delegates in question to Eisenhower by default, thus earning Eisenhower the nomination. Eisenhower then went on to win the general election in a landslide, finally putting a Republican president in the White House for the first time since 1933.

1956

As a popular incumbent, with a strong economy and recent foreign policy victories including the
Korean War, Eisenhower easily won his party's primaries in 1956 with little opposition, namely former candidate John Bricker from 1944, as well as
Joe Foss of South Dakota and S.C. Arnold of Montana.

1960

With Eisenhower term-limited from office, the clear frontrunner for the Republican nomination was incumbent vice president
Richard Nixon, who was also very popular in his own right. He won 11 primaries, while his only two major challengers, Governor
Cecil Underwood of West Virginia and State Senator
James M. Lloyd of South Dakota, only won their respective home states. Thus, Nixon easily won the nomination, and selected longtime Eisenhower ally Henry Cabot Lodge, Jr. as his running mate.

1964

Despite Nixon's continuing popularity, and the closeness by which he lost in 1960, he refused to seek the Republican Party's nomination in 1964, primarily due to his previous loss as well as another equally stinging loss in the
1962 California gubernatorial race. Thus, the party was left without a clear frontrunner. For the first time, the divide between conservatives and moderates allowed the conservative candidate, Senator
Barry Goldwater of Arizona to win the nomination despite his unpopular, strong conservative views. His biggest challengers were Henry Cabot Lodge, Jr., with 3 primary wins, and Governor
Nelson Rockefeller of New York with 2; however, despite both candidates' strong alliances in the liberal wing of the party (including Lodge's continuing alliance with former President Eisenhower), both were far surpassed by Goldwater's surprising 7 victories. Other candidates included Governor
James A. Rhodes of Ohio, Governor
William Scranton of Pennsylvania, and Congressman
John W. Byrnes of Wisconsin, who each won their own respective home states and nothing else. Also among the candidates was Senator
Margaret Chase Smith of Maine, who became the first major female candidate for a major party's presidential nomination in American history.

1968

Despite Goldwater's landslide loss to President Johnson in 1964, the struggling economy and the escalation of the unpopular
Vietnam War led to Johnson's approval ratings falling dramatically, to the point where he refused to seek another term in 1968. Thus, many in the Republican Party felt that they had a strong chance of winning, and turned to former Vice President and 1960 nominee Richard Nixon to run again. Despite previously claiming he was done with politics after losing in 1960 and 1962, Nixon ultimately decided to join the race. As a moderate, Nixon faced a series of challengers from all sides of the Republican political spectrum who would rise briefly, then fall again in popularity just as another challenger arose. His first challenger was a fellow moderate, Governor
George W. Romney of Michigan. Romney's record as Governor briefly elevated him with Nixon, but after a gaffe where he said he was "brainwashed" by the military into supporting the Vietnam War, he quickly lost his popularity and dropped out before the primaries even started. Nixon's next challenge was the leader of the party's liberal wing, New York Governor Nelson Rockefeller, who briefly rose in popularity with his win in Massachusetts before fading in the polls as well. By the end of the primaries, Nixon's main challenge was Governor
Ronald Reagan of California, the leader of the party's conservative wing. Although Reagan's victory in his home state gave him a plurality of the popular vote, he didn't win any other primaries. Nixon won a total of 9 primaries before easily winning the nomination at the convention. Despite some supporters encouraging him to choose a former primary rival, such as Romney, as his running mate, Nixon ultimately chose Maryland Governor
Spiro T. Agnew.

1972

By 1972, Nixon was a popular incumbent president. The
Vietnam War was winding down and Nixon had achieved
détente with
China and the
Soviet Union, as well as a stable economy at home and solidified victories in the
Civil Rights Movement. He had challengers, but won 1323 of the 1324 delegates on his way to the GOP convention. The sole delegate opposing his reelection was in support of
Pete McCloskey, a representative from
California, who ran on an anti-Vietnam War platform. The
Watergate scandal began in June but interfered with neither the primaries nor the November election.

1976

Gerald Ford had become Vice President after the resignation of Vice President
Spiro Agnew. Upon the resignation of President
Richard Nixon following the
Watergate Scandal, Ford became the first President never elected President or Vice-President. This status, plus the fall of Vietnam, a struggling economy, and Ford's pardon of Nixon, caused politicians in both major parties to view Ford as vulnerable.
Ronald Reagan led the conservative wing of the party in condemning Ford's foreign policy in
Vietnam,
Eastern Europe and
Panama. Ford held a lead from the beginning until the North Carolina primary, where he was upset by Reagan. Reagan then put together a string of victories throughout the South that put him back in the race. Ford bounced back in his native Michigan. From there, a close battle in the remaining states led to a convention in which Ford held the lead, but not the necessary majority. Reagan gambled by announcing he would choose moderate
Pennsylvania Senator
Richard Schweiker as his running mate - the move ultimately backfired by alienating conservatives. Ford narrowly won on the first ballot, and avoided the same mistake as Reagan by choosing conservative
Kansas Senator
Bob Dole as his running mate.

1980

Ronald Reagan entered the season as the overwhelming favorite to win the nomination. He lost his lead with a strategy of forums, polls and other events.
George H. W. Bush used the
McGovern/
Carter strategy and began to come in first at these events. Bush beat Reagan in the Iowa straw poll in January. Reagan responded by sweeping the South. Although he lost a few more primaries and even came in third in one state, he had the contest won early, and went into the convention with almost all the delegates. Although Reagan was initially prepared to choose former President Gerald Ford as his running mate, he found that too many of Ford's conditions were asking for so much power that Ford would be more of a "co-President" rather than a Vice President. Thus, just hours before Reagan had to make his decision, Reagan ultimately chose Bush as his running mate.

1988

George H. W. Bush entered the contest as incumbent Vice-President and with the support of sitting President
Ronald Reagan. Bush had trouble at first but by the time
Super Tuesday was over his campaign's organization and fundraising ability had overwhelmed his opponents. He received all the votes at the convention.

1992

Pat Buchanan mounted a challenge that was too weak to seriously challenge President
George H. W. Bush's campaign for a second term. However, it was strong enough to alter the party platform and push it to the right, and to award Buchanan the keynote speech at the convention.

1996

Bob Dole, the
Kansas Senator and
Senate Majority Leader, who was also the vice-presidential nominee 20 years earlier in 1976, was widely viewed as the most prominent Republican in the race. As he had been widely expected to compete for the 1996 presidential nomination ever since the 1992 campaign, he was the early favorite to win. However, his campaign stumbled in the first few contests as it fell behind conservative insurgent
Pat Buchanan in New Hampshire and publishing magnate
Steve Forbes in Delaware and Arizona. Dole rebounded with easy victories in the Dakotas and South Carolina, eventually winning every single state thereafter, save a narrow Buchanan win in Missouri.

2000

George W. Bush entered the race as the favorite, being the son of a former president and the governor of a big state. He faced early opposition from the well-organized campaign of wealthy businessman
Steve Forbes, who quickly fizzled. Bush easily won in Iowa but suffered a severe blow when
Arizona Senator
John McCain emerged as an insurgent candidate and defeated him in New Hampshire by 18 points. Bush struck back with a win in South Carolina after a bruising primary fight there. McCain rebounded with wins in Michigan and his home state of Arizona, but lacked the money and organization to keep up with Bush in the Super Tuesday contests, where Bush won all but a few New England states. McCain suspended his campaign the next day.

2008

George W. Bush, the incumbent President, was ineligible to run for a third term due to the
Twenty-second Amendment, and
Dick Cheney, the incumbent Vice President, did not seek the office, so the field was wide open. Former
New York City Mayor
Rudy Giuliani was the frontrunner in the polls for most of 2007, but made a critical mistake by skipping the early primaries and staking his fortune on a win in Florida the week before Super Tuesday. This backfired badly as
John McCain, the runner-up of the 2000 primaries, whose campaign had been written off long before as a lost cause, surged suddenly in New Hampshire and rode a wave of momentum through South Carolina to defeat all other contenders in Florida. Giuliani quickly dropped out and endorsed McCain, but former
Massachusetts Governor
Mitt Romney, a well-organized candidate who up to that point had won only his native Michigan and a couple minor caucus states, fought on. McCain easily beat him on Super Tuesday, with assistance from former
Arkansas Governor
Mike Huckabee, a conservative contender who stole a few crucial Southern primaries, thus shutting Romney out. Romney suspended his campaign during the
CPAC convention that week, leaving only Huckabee, who said he would stay in until the nomination fight was over. He dropped out in early March after McCain won Texas and Ohio, thus clinching the nomination.
Texas Congressman
Ron Paul, who had generated a lot of Internet buzz, but did not win a single contest, stayed in the race until the last primary votes were cast in June.

2012

For the first time in modern Republican primary history, three different candidates won the three key early contests: Former
Pennsylvania Senator
Rick Santorum in the
Iowa caucuses (though Romney was originally believed to have won before a recount),
Mitt Romney in the
New Hampshire primary, and former
Speaker of the HouseNewt Gingrich in the
South Carolina primary. However, only Romney and Santorum seemed to project national strength, as Gingrich's only win after South Carolina would be his home state of Georgia.
Ron Paul, who had been expected to perform much better than he did in 2008, only scored second-place finishes in contests such as New Hampshire and Virginia (where only he and Romney were on the ballot), and a narrow win in the popular vote in the U.S. Virgin Islands. However, he did have the most second-place wins overall. Romney maintained the upper hand throughout the primaries, winning most of the Super Tuesday contests and holding onto a wide lead in delegates. Santorum's final efforts included a surprise victory in the Colorado caucuses, which Romney was expected to win, and narrow second-place performances in Michigan and Ohio. Santorum dropped out of the presidential race on April 10, leaving Romney undisputed in his drive for the party's nomination.

2016

The 2016 GOP primaries featured the largest field in the history of both major parties, with
17 major contenders eventually announcing bids. Businessman
Donald Trump announced he was running for president in the summer of 2015 and dominated most Republican polling from that point on. He suffered an early upset in the
Iowa caucuses, which were won by
Texas Senator
Ted Cruz, with
Florida Senator
Marco Rubio finishing an unexpectedly strong third, essentially narrowing the contest to a three-way race. Trump rebounded and carried the remainder of the early contests, and came out on top in the
Super Tuesday contests. Cruz, however, won his home state of Texas, giving him a strong boost going forward. Rubio managed only wins in Minnesota, Puerto Rico and the District of Columbia before losing his home state of Florida to Trump and being forced to drop out. Governor
John Kasich of Ohio, who had placed second in New Hampshire, won his home state, but nowhere else. It was heavily speculated that Trump would not win the required number of delegates to clinch the nomination, resulting in a
contested convention in
Cleveland. However, those fears were laid to rest after Trump swept six Northeastern states (including his home state of New York), and decisively won Indiana, a state that Cruz needed in order to continue his campaign. Both Cruz and Kasich suspended their campaigns afterward, leaving Trump as the only candidate left and the presumptive nominee.

Former
Hewlett-Packard CEO
Carly Fiorina, who had dropped out of the race after New Hampshire, was chosen as the first vice-presidential running mate of the campaign, in a highly unusual move by Cruz, six days before he dropped out.